Two double-blind, randomized, split-face studies have been performed to compare the facial tolerability of topical retinoids in volunteers with sensitive skin. In one study, subjects applied tazarotene 0.1% gel to one side of their face and tretinoin 0.1% gel microsponge, tretinoin 0.025% gel, or adapalene 0.1% gel to the other side of their face, for up to 29 days. Increases in facial dryness and erythema were comparable among all retinoids. Some subjects in each treatment group experienced levels of retinoid-associated irritation that required temporary suspension of, or reduction in, treatment. Facial dryness and erythema tended to be greater in these subjects than in those who tolerated the regimen without change, suggesting that the need to discontinue or modify treatment depends more on the individual than on any major inherent differences in the irritant potential of these retinoids. A second study compared once-daily versus alternate-day tazarotene 0.1% gel therapy. Tolerability was superior when initiating therapy with the alternate-day regimen.